| Level I | Good quality evidence |
Systematic review of RCTs with consistent findings High quality individual RCT |
| Level II |
Limited quality patient orientated evidence |
Systematic review of lower quality studies or studies with inconsistent findings Low quality clinical trial Cohort studies Case-control studies |
| Level III | Other |
Consensus guidelines, extrapolations from bench research, usual practice, opinion, disease-oriented evidence (intermediate or physiologic outcomes only), or case series |
[22] Selective serotonin reuptake inhibitors, oral (in pregnancy): National Institute for Health and Clinical Excellence (NICE). Antenatal and postnatal mental health: the NICE guideline on clinical management and service guidance. Updated edition. NICE clinical guidance 192. London: NICE; 2014. Available from: https://www.nice.org.uk/guidance/cg192/evidence/full-guideline-pdf-19339686
Selective serotonin reuptake inhibitors, oral (in pregnancy): British Association for Psychopharmacology consensus guidance on the use of psychotropic medication preconception, in pregnancy and postpartum 2017. McAllister-Williams RH, Baldwin DS, Cantwell R, Easter A, Gilvarry E, Glover V, Green L, Gregoire A, Howard LM, Jones I, Khalifeh H, Lingford-Hughes A, McDonald E, Micali N, Pariante CM, Peters L, Roberts A, Smith NC, Taylor D, Wieck A, Yates LM, Young AH, endorsed by the British Association for Psychopharmacology. J Psychopharmacol. 2017;31:519. Available from: https://www.bap.uk